^ She doesn't hate all politicians. She was an enthusiastic supporter of the last Labout government, even under Gordon Brown.
Indeed, she and the former Prime Minister are good friends, apparently.
Rowling's attitude towards politicians and political leaders is a bit more complex than just dislike -- even in the Harry Potter
books, some political leaders are seen in a good light, and many of the main characters go on to work for the Ministry of Magic. It's not that she's anti-politician, per se, so much as it is that she depicts political systems as often falling into the hands of people who are more interested in power and self-glorification than in good governance.